Economies are studied where labor contracts, even without changing real allocations, can make equilibria appear different. One basic example is that wage observations generated by long-term employment contracts are biased measures of theoretical market wages. This idea is analyzed in a dynamic, stochastic, economic model, including both overlapping generations of finite-lived workers and infinite-horizon employers, so that the implications for business cycle, life cycle, and cross-sectional phenomena can be explicitly addressed. Understanding contracts in this way potentially allows us to reconcile several ostensibly anomalous aspects of the data with equilibrium theory.

A model of labor supply under uncertainty is developed, and comparative statics of current labor are carried out with respect to temporary and persistent wage change. This and a complementary analysis of measurement error suggest that individual wage growth leads to downward-biased estimates of intertemporal labor substitution. An alternative strategy, namely, the use of short-lived industry wage pulses in place of individual wage growth, is free of the above biases. Findings presented in the paper support this point of view. These results also suggest that intertemporal substitution has been undervalued as a source of cyclical changes in unemployment.

I analyze job search models with random layoffs in which employment opportunities are characterized by a wage and some measure of risk. Intuition suggests that a worker ought to demand a higher wage if he is to accept a job with a higher layoff rate; but this is not true in several models analyzed in the literature. I demonstrate here that assumptions about what happens immediately after a layoff and after a quit are critical in determining the relation between reservation wages and risk. Making these assumptions explicit clarifies the reasons why different models imply quite different predictions.

The utility of machine learning (ML) for regression-based causal inference is illustrated by using lasso to select control variables for estimates of college characteristics’ wage effects. Post-double-selection lasso offers a path to data-driven sensitivity analysis. ML also seems useful for an instrumental variables (IV) first stage, since two-stage least squares (2SLS) bias reflects overfitting. While ML-based instrument selection can improve on 2SLS, split-sample IV and limited information maximum likelihood do better. Finally, we use ML to choose IV controls. Here, ML creates artificial exclusion restrictions, generating spurious findings. On balance, ML seems ill-suited to IV applications in labor economics.

Most research on the relationship between teacher characteristics and pupil achievement focuses on salaries, experience, and education. The effect of in‐service training has received less attention. We estimate the effect of in‐service teacher training on achievement in Jerusalem elementary schools using a matched‐comparison design. Differences‐in‐differences, regression, and matching estimates suggest training in secular schools led to an improvement in test scores. The estimates for religious schools are not clear cut, perhaps because training in religious schools started later and was implemented on a smaller scale. Estimates for secular schools suggest teacher training provided a cost‐effective means of increasing test scores.

Until 1983, the language of instruction for most subjects in grades 6 and above in Moroccan public schools was French. Beginning in 1983, the language of instruction for new cohorts of Moroccan sixth graders was switched to Arabic. We use this policy change to estimate the effect of French language skills on test scores and earnings. The estimates suggest that the elimination of compulsory French instruction led to a substantial reduction in the returns to schooling for Moroccans affected by the change. This reduction appears to be largely attributable to a loss of French writing skills.

Relicensing requirements for professionals who move across borders are widespread. In this article, we measure the effects of occupational licensing by exploiting an immigrant physician retraining assignment rule. Instrumental variables and quantile treatment effects estimates indicate large returns to acquiring an occupational license and negative selection into licensing status. We also develop a model of optimal license acquisition that, together with the empirical results, suggests that stricter relicensing requirements may lead not only to practitioner rents but also to lower average quality of service in the market for physicians.

We examine the impact of immigration on self‐employed natives. In a new general equilibrium model of self‐employment and wage/salary work, a range of plausible parameter values implies small negative effects of immigration on native self‐employment rates and earnings. Using 1980 and 1990 Census microdata, we then examine the relationship between changes in immigration and native self‐employment rates and earnings across 132 of the largest U.S. metropolitan areas. We find evidence suggesting that self‐employed immigrants displace self‐employed natives but do not have a negative effect on native self‐employment earnings. The effects are much larger than those predicted by the theoretical model.

We survey unemployment insurance (UI) in the United States and provide new evidence on the UI payroll tax. Most UI receipt is due to firms that pay part of the UI costs of their layoffs, but weak experience rating leads most firms to pay considerably less than the full costs. Industries consistently receiving subsidies from the UI system are construction, manufacturing, and mining. Finally, a large fraction of layoffs resulting in payment of UI are made by firms that are not charged for the costs of the claim because they have employed the individual for less than 2 quarters.

There are persistent differences in self-reported subjective well-being across US metropolitan areas, and residents of declining cities appear less happy than others. Yet some people continue to move to these areas, and newer residents appear to be as unhappy as longer-term residents. While historical data on happiness are limited, the available facts suggest that cities that are now declining were also unhappy in their more prosperous past. These facts support the view that individuals do not maximize happiness alone but include it in the utility function along with other arguments. People may trade off happiness against other competing objectives.